1. Field of the Invention
The present invention relates to the field of manufacturing liquid crystal display panels, and in particular to a polarizing sheet removing tool and removing method.
2. The Related Arts
Liquid crystal displays (LCDs) have numerous advantages, such as thin device body, less power consumption, and being free of radiation, and is thus widely used. Most of the flat panel display devices available in the market are backlighting liquid crystal displays, which comprise a liquid crystal display panel and a backlight module. The operation principle of the liquid crystal display panel is that liquid crystal molecules are arranged between two parallel glass substrates and electricity is selectively applied to circuits of the glass substrates to control change of the orientation of the liquid crystal molecules in order to refract out the light from a backlight module for formation of an image.
Referring to FIG. 1, a liquid crystal display panel is generally composed of a thin-film transistor (TFT) substrate 100, a color filter (CF) substrate 300 that is laminated on the TFT substrate 100, and liquid crystal 500 interposed between the TFT substrate 100 and the CF substrate 300. Both the TFT substrate 100 and the CF substrate 300 comprise a polarizing sheet 700 laminated thereon. The polarizing sheet 700 is an optic film that is formed by combining multiple layers of polymer materials to have a function of polarizing light and is laminated on the surface of the TFT substrate 100 that is distant from the CF substrate 300 and the surface of the CF substrate 300 that is distant from the TFT substrate 100 to convert non-polarized natural light into polarized light, allowing light that is in a direction perpendicular to the electric field to pass. This makes the liquid crystal display panel normally displaying an image. Apparently, the polarizing sheet is one of the key components that affect the displaying performance of a liquid crystal display panel.
The polarizing sheet is bonded to the liquid crystal display panel by adhesives, so that an adhesion force is present between the polarizing sheet and the liquid crystal display panel. Although the industry does not set up technical specifications for the adhesion force, yet for example, the adhesion force may not be excessively small in order to prevent the polarizing sheet from self-peeling or warping and the adhesion force may also not be excessively large otherwise subsequent maintenance operations may be affected. However, it is inevitable that the adhesion force interferes with the removal of the adhesion force to some extents.
Based on analyses conventionally made on defect products found in manufacturing processes, in order to remove a portion of the polarizing sheet from a liquid crystal display panel when a problem associated with the polarizing sheet occurs, the conventional way is using a cutter to cut the polarizing sheet to be peeled off into a square area (of which the size is determined according to practical needs) and then using the cutter to separate the polarizing sheet from the glass in order to peel off the polarizing sheet. However, it is often that the adhesion force is relatively strong and it is hard to completely peel off the polarizing sheet. Generally, a major portion of adhesive is left on the glass. This portion of adhesive is difficult to remove and removal is usually done by applying the cutter multiple times. This severely affects the speed and result of peeling of polarizing sheet and lowers down the efficiency of experimental analyses.